Battery sensor

Abstract

There is provided a battery comprising an electrochemical unit comprising at least one electrochemical cell. The at least one electrochemical cell comprises a cell anode, a cell cathode and an electrolyte in contact with said cell anode and cell cathode. The electrochemical unit further comprises a first contact electrode mounted on a surface of the electrochemical unit. The battery further comprises a second contact electrode positioned adjacent to the electrochemical unit, whereby the first and second contact electrodes face each other to allow a contact resistance between the first contact electrode and second contact electrode to be measured.

The invention claimed is: 
     
       1. A battery comprising:
 an electrochemical unit comprising at least one electrochemical cell and a first contact electrode mounted on a surface of the electrochemical unit, the at least one electrochemical cell comprising a cell anode, a cell cathode, and an electrolyte in contact with the cell anode and the cell cathode; 
 a second contact electrode positioned adjacent to the electrochemical unit, the first contact electrode and the second contact electrode being arranged to face each other to allow a contact resistance between the first contact electrode and the second contact electrode to be measured; and 
 a device configured to measure the contact resistance between the first contact electrode and the second contact electrode, the measured contact resistance between the first contact electrode and the second contact electrode being indicative of contraction and/or expansion of the electrochemical cell. 
 
     
     
       2. A battery as claimed in  claim 1 , wherein the second contact electrode is mounted on a surface of a battery case configured to house the electrochemical unit. 
     
     
       3. A battery as claimed in  claim 1 , further comprising a second electrochemical unit comprising at least one electrochemical cell that comprises a cell anode, a cell cathode, and an electrolyte in contact with the cell anode and the cell cathode, wherein the second contact electrode is mounted on a surface of the second electrochemical unit. 
     
     
       4. A battery as claimed in  claim 1 , wherein the cell anode comprises a lithium anode, and wherein the cell cathode comprises a mixture of an electroactive sulphur material and an electroconductive material. 
     
     
       5. A battery as claimed in  claim 4 , wherein the electrochemical unit is separated from an adjacent electrochemical unit by a dividing member on which the second contact electrode is mounted. 
     
     
       6. A battery as claimed in  claim 5 , wherein the dividing member comprises a sheet of metal foil. 
     
     
       7. A battery as claimed in  claim 6 , wherein the dividing member further comprises a sheet of insulating material. 
     
     
       8. A battery as claimed in  7 , wherein the second contact electrode is formed from an electrical conductor deposited on a surface of the dividing member. 
     
     
       9. A battery as claimed in  claim 8 , wherein the electrical conductor comprises a conductive pattern. 
     
     
       10. A battery as claimed in  claim 8 , wherein the electrical conductor comprises a carbon black material. 
     
     
       11. A battery as claimed in  claim 8 , wherein the second contact electrode is formed by at least applying, a paste on the surface of the dividing member, the paste comprising a carbon black material and a binder. 
     
     
       12. A battery as claimed in  claim 11 , wherein the first contact electrode and the second contact electrode are provided with contact tabs configured to contact the device for measuring the contact resistance between the first contact electrode and the second contact electrode. 
     
     
       13. A battery as claimed in  claim 12 , wherein the battery comprises more than two electrochemical units. 
     
     
       14. A battery as claimed in  claim 13 , wherein each electrochemical unit comprises a plurality of electrochemical cells. 
     
     
       15. A battery as claimed in  claim 1 , further comprising a battery management system, the battery management system comprising:
 at least one processor; and 
 a memory comprising instructions which, when executed, cause the at least one processor to at least:
 receive a contact resistance value; 
 compare the contact resistance value with at least one previous contact resistance value, the at least one previous contact resistance value corresponding to at least one known state of charge of the battery; and 
 estimate a state of charge of the battery based at least in part on comparing the contact resistance value with the at least one previous contact resistance value. 
 
 
     
     
       16. A battery as claimed in  claim 15 , wherein the memory further comprises instructions which, when executed, further cause the at least one processor to at least estimate a state of health of the battery based at least in part on the contact resistance value and the estimated state of charge of the battery. 
     
     
       17. A battery as claimed in  claim 1 , further comprising:
 at least one processor; and 
 a memory comprising instructions which, when executed, cause the at least one processor to at least:
 receive a contact resistance value; 
 compare the contact resistance value with a plurality of previous contact resistance values, each of the plurality of previous contact resistance values corresponding to a known state of charge of the battery; and 
 estimate a state of health of the battery based at least in part on the contact resistance value being compared with the plurality of previous contact resistance values. 
 
 
     
     
       18. A method comprising:
 measuring, by a resistance measurement device, a contact resistance value between a first contact electrode and a second contact electrode, the first contact electrode being mounted on a surface of an electrochemical unit, the electrochemical unit comprising at least one electrochemical cell, the at least one electrochemical cell comprising a cell anode, a cell cathode, and an electrolyte in contact with the cell anode and the cell cathode, the second contact electrode being positioned adjacent to the electrochemical unit, the first contact electrode and the second contact electrode facing each other to allow the contact resistance between the first contact electrode and the second contact electrode to be measured, the measured contact resistance between the first contact electrode and the second contact electrode being indicative of contraction and/or expansion of the electrochemical cell; and 
 estimating, based on the measured contact resistance value, a state of charge of a battery. 
 
     
     
       19. The method of  claim 18 , wherein estimating the state of charge of the battery further comprises:
 comparing the measured contact resistance value with at least one previous contact resistance value, the at least one previous contact resistance value corresponding to a known state of charge of the battery; and 
 estimating, based on the comparing, the state of charge of the battery.